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Biomedical subjects

R Chen

Publications and source records attributed to R Chen.

At least 325 records · Page 18Linked to original sources

A comparison of triamcinolone acetonide MDI with a built-in tube extender and beclomethasone dipropionate MDI in adult asthmatics.

STUDY OBJECTIVE: In this study, the efficacy and safety of triamcinolone acetonide (TA) metered-dose inhaler with a built-in tube extender and beclomethasone dipropionate (BDP) metered-dose inhaler without a spacer device were compared. Both treatments were dosed at their most commonly used daily doses (within labeling). DESIGN: A 56-day, randomized, double-blind, double-dummy, placebo-controlled trial. SETTING: Seventeen asthma/allergy centers. PATIENTS: We enrolled 339 patients 18 to 65 years of age, with a documented history of bronchial asthma (FEV1, 50 to 90% of predicted value) for > or = 2 years who required inhaled corticosteroid therapy. INTERVENTIONS: Patients were randomized to receive BDP 336 microg/d (4 puffs bid) plus TA placebo (4 puffs bid), TA 800 microg/d (4 puffs bid) plus BDP placebo (4 puffs bid), or TA and BDP placebos (4 puffs of each bid). The only other asthma medication permitted was inhaled albuterol that was used as a rescue medication. All medications were administered via the closed-mouth inhalation technique. MEASUREMENTS AND RESULTS: At 8 weeks and at study end point, both active treatment groups had statistically significant and comparable improvements in FEV1 relative to baseline, and statistically significant increases relative to placebo. At study end point, improvements in forced expiratory flow (FEF25.75%), clinic peak expiratory flow (PEFR), and FVC were statistically significant for the active treatment groups compared with placebo. At end point, the mean difference between BDP and TA for mean change in FEV1 from baseline in the efficacy population was 0.02 and the 95% confidence interval was -0.11, 0.15. Asthma symptoms recorded at clinic visits showed statistically significant improvements for the BDP and TA groups compared with the placebo group. Treatment-related adverse events occurred with similar frequency in all patient groups-25.5% of placebo-treated patients, 22.3% of BDP patients, and 20.4% of TA patients. The incidence of oropharyngeal adverse events, including cough, thrush, and dysphonia, was not statistically different between the two active treatment groups. CONCLUSION: In this randomized, double-blind, placebo-controlled study of adult asthmatics treated with either BDP without a spacer or TA with its built-in tube extender, BDP and TA were comparable in efficacy as measured by FEV1 and other pulmonary function tests, and by improvement in asthma symptoms. Both active treatments were significantly more effective than placebo. All treatment groups were comparable in safety as measured by the incidence of adverse events.

Administration, Inhalation↗

[A prospective study on accidental deaths among 0-14-year-old children in Jiangsu, 1994-1995].

By stratified cluster random sampling, a prospective study on the accidental deaths of 0-14 years old children during 1994-1995 wsa carried on in a population size of 2.29 millions in four citys and nine counties in Jiangsu province. Results showed that the average mortality of accidents was 53.0 per 10(5) among children aged 0 to 14 and accidental death was the leading cause of deaths taking up 37.6% among the deaths of the 0-14 years old. Accidental deaths ranked fourth, took up 15.3% in infancy deaths making up about 70% in their deaths, and ranked first in the age groups 1-4 and 5-14. The three leading causes of accidental deaths in the urban and rural area were drowning, accidental suffocation and motor vehicle injuries. Accidental suffocation was the number one cause of accidental death in infants, making up 85% of the total accidental deaths. Drowning was the leading cause of accidental deaths in 1-4 and 5-14-year-old children, making up 70% and 50% of accidental deaths respectively. Motor vehicle injuries took the lead among accidental deaths in the cities.

Accidents↗

[Experimental study of proliferation effects of platelet derived wound healing factor on tissue cells of wound].

This experiment was designed to observe the proliferative effects of platelet derived wound healing factor (PDWHF) of different concentrations on fibroblasts from rat wounds and on epithelial from human wounds. Cultured fibroblasts from rat wound and epithelia from human wound were randomly divided into three groups. (1) In blank control, the cells were treated with basic medium (BM, contains 1640/0.5% FCS); (2) the positive control, the cells were treated with 1640/10% FCS and (3) in the PDWHF group, the cells were treated respectively with BM/1% PDWHF, BM/3% PDWHF, BM/5% PDWHF, BM/7% PDWHF, BM/10% PDWHF, BM/12% PDWHF, respectively. The Cells were collected after 48 hours culturing with BM or PDWHF, and the cell proliferation was measured by MTT method according to the OD values. The result showed that the PDWHF could remarkably enhance the proliferation of fibroblasts and epithelial cells when its concentration was between 1% and 7%, which was obviously higher than that of the blank control (P < 0.01). When the concentration of PDWHF reached 10%, its proliferative effect was not remarkable when compared with the blank control, When the concentration of PDWHF reached 12%, it showed inhibitory effect on fibroblasts and manifested no obvious inhibitory effect on epithelial cells. It was concluded that the PDWHF was a combination of a variety of growth factors. In a certain range of concentration, the PDWHF might effectively promote the proliferation of fibroblasts and epithelial cells. Howerve, when its concentration reached to relatively higher level, its effect was not remarkable any more, or even showed inhibitory effect on cell proliferation.

Animals↗

[Study on relationship between apoptosis and proliferation of cells in liver cirrhosis and hepatocellular carcinoma].

Apoptosis and nuclear antigen of proliferating cells were detected by labelling technique of in situ terminal deoxynucleotide transferase and immunohistochemical method in liver cirrhosis and hepatocellular carcinoma(HCC). The density of apoptotic cells in HCC was significantly lower than that in cirrhosis, and the density of proliferating cells was much higher in HCC than that in cirrhosis. Apoptotic cells mainly distributed in the peripseudolobular region of cirrhosis and formed an apoptosis zone. But they scattered within the cancer tissue. The results suggest that the formation of apoptosis zone in cirrhosis may be related to the change of liver blood stream. Selective proliferation of cells may exist during carcinogenesis of liver cirrhosis.

Adult↗

[An improved method of cholesterol determination in egg yolk by high performance liquid chromatography].

An improved method for cholesterol determination in egg yolk is reported in this paper. Egg yolk was first diluted. Cholesterol was then extracted with ethyl ether and petroleum ether, and quantified by reversed phase liquid chromatography on a Zorbax ODS column (0.46 mm x 15 cm, 5-6 microns) using a mobile phase of acetonitrile and 2-propanol (4:1) with a flow rate of 0.6 mL/min. A linear correlation was observed between 0.05-0.40 g/L of cholesterol. The determination limit was 0.02 g/L. This proposed method of HPLC determination of egg yolk without saponification is superior to colorimetric determination on the sample with saponification, and comparable to HPLC determination with saponification of the egg yolk sample in terms of reliability. No difference in final results was observed between egg yolk sample with saponification and the same sample without saponification. Rapid and reproducible quantification of cholesterol in egg yolk can be completed with this new method. Omission of saponification has made this proposed method more convenient than those ever reported, and can be used in yolk cholesterol study with greater ease.

Cholesterol↗

[Application of VNTR D17S30 locus polymorphism in the paternity test].

A sensitive and rapid PCR-based technique was adopted to genotype the VNTR D17S30 locus. It was confirmed through the genetic analysis of 20 normal families that the inheritance of D17S30 locus coincides with Mendelian law as simple co-dominant. Retrospective analysis of 100 paternity cases demonstrated that D17S30 locus could be used in forensic paternity test in our country. The exclusion probability estimated from allele frequencies of D17S30 locus (74.04%) does not differ significantly from the observed rate of exclusion (80.00%) in these cases. In all excluded paternity cases there are two in which the exclusion evidence is solely provided by the D17S30 locus.

Chromosomes, Human, Pair 17↗

Molecular genetics of root gravitropism and waving in Arabidopsis thaliana.

When Arabidopsis thaliana seedlings grow embedded in an agar-based medium, their roots grow vertically downward. This reflects their ability to sense the gravity vector and to position their tip parallel to it (gravitropism). We have isolated a number of mutations affecting root gravitropism in Arabidopsis thaliana. One of these mutations, named arg1, affects root and hypocotyl gravitropism without promoting defects in starch content or in the ability of seedlings' organs to respond to plant hormones. The ARG1 gene was cloned and shown to code for a protein with a J domain at its amino terminus and a second sequence motif found in several cytoskeleton binding proteins. Mutations in the AGR1 locus promote a strong defect in root gravitropism. Some alleles also confer an increased root resistance to exogenous ethylene and an increased sensitivity to auxin. AGR1 was cloned and found to encode a putative transmembrane protein which might be involved in polar auxin transport, or in regulating the differential growth response to gravistimulation. When Arabidopsis seedlings grow on the surface of agar-based media tilted backward, their roots wave. That wavy pattern of root growth derives from a combined response to gravity, touch and other surface-derived stimuli. It is accompanied by a reversible rotation of the root tip about its axis. A number of mutations affect the presence or the shape of root waves on tilted agar-based surfaces. One of them, wvc1, promotes the formation of compressed root waves under these conditions. The physiological and molecular analyses of this mutant suggest that a tryptophan-derived molecule other than IAA might be an important regulator of the curvature responsible for root waving.

Arabidopsis↗

[A study on the characteristics of articulation for functional speech problem after cleft palate surgery].

OBJECTIVE: To analyze the characterisctics of articulatory errors for the patients with speech problem and whose anatomic or physiologic defect such as velopharyngeal insufficiency were not indicated after cleft palate surgery. METHODS: Fifty patients with functional speech problem outlined above were tested using articulation test in chinese. The frequency of articulatory errors of all consonants was calculated. The interrelativity of the rate of affricates and plosives errors was analyzed. RESULTS: The frequency of affricates (j. z. ch. zh. et al) errors was higher than plosive's (b.d.g.k. et al). The difference of the rate of affricates and plosives errors was significant, statiscally (P < 0.001). CONCLUSION: It is suggested that the frequency of affricates errors was principal in this type of patients. They will be cured by speech training.

Adolescent↗

[Thoracoscopic lung reduction surgery for emphysema].

OBJECTIVE: To study the surgical treatment of emphysema. METHOD: Five patients with severe diffused pulmonary emphysema underwent surgical bilateral lung volume reduction by video-assisted thoracoscopy. All patients were male and their age ranged from 60 to 71 years (mean 64.3 years). Before surgery, 5 patients required supplement oxygen with exertion and one oxygen supplement at rest. Preoperative and postoperative assessments included standard pulmonary function studies, chest CT scan and quantitative nuclear lung perfusion and ventilation scan. Wedge resection was performed were in 3 patients, simple plication in 1, and combined wedge resection and plication in 1. There were no early or late mortality and no requirement for immediate postoperative ventilatory assistance. RESULT: Follow-up ranged from 10 to 12 months. After surgery the mean forced expiratory volume in 1 second (FEV(1)) was significantly increased from 0.46 L to 1.13 L (P < 0.001) and the mean forced vital capacity (FVC) was markedly improved from 1.74 L to 2.93 L (P < 0.001). Pulmonary compliance was significantly improved and resistance of airway decreased (P < 0.001). The mean distance during 6-min walk test increased from 10 m to 400 m in 4 patients. CONCLUSION: Thoracoscopic bilateral lung volume reduction is an effective and safe technique for patients with severe emphysema. It can relieve dyspnea and improve in excise tolerance and quality of life.

Aged↗

[A study on the mechanism of apomorphine for treatment of myopia].

OBJECTIVES: To investigate the functions of dopamine D(1) and D(2) receptor in form deprivation myopia (FDM) and the influence of apomorphine (Apo) on inhibition of FDM in chick with radioligand binding assay (RBA). METHODS: All chicks after hatching were divided into three groups: unilateral lid suture, lid-suture and treated with Apo subconjunctival injections and normal control. After two weeks, they were refracted, then were killed, their equator dimensions of the eyeballs were measured quickly, the retinas were dissected out and pooled into three above separate groups. [(3)H]SCH 23390 and [(3)H] Spiperone were used for the saturation tests for D(1) and D(2) receptor protein respectively in the three groups. RESULTS: The numbers of both dopamine receptors in FDM increased (up-regulation). With the treatment of Apo, the numbers of both dopamine receptors decreased (down-regulation). The affinities of both receptors were of no difference. CONCLUSIONS: The dopamine receptors in chick retina are under hypersensitive state in FDM, that is related to the biological level lowering of dopamine. Apo can inhibit the development of myopia, and the D(1) and D(2) receptor numbers are decreased, showing that Apo can affect dopamine receptors in various degrees. The method of this study can provide a route to screen drugs for treatment of myopia.

Animals↗

[A reversed phase HPLC method with pre-column derivatization to determine propafenone enantiomers in human plasma].

A reversed phase HPLC method to stereoselectively determine enantiomers of propafenone in human plasma has been developed. After extraction of 1 ml plasma with 3 ml of n-C6H14:CH2Cl2:2-C3H7OH (100:50:5, v/v) and dried under N2, the enantiomers of propafenone were allowed to react with homochiral S(+)-1-(1-naphthyl) ethyl isocyanate (5.66 micrograms in 60 microliters CH2Cl2) at RT for 30 min, to give the diastereomeric derivatives. Their separation was achieved using HPLC with a C18-column and UV-detection (220 nm) and the enantiomeric ratios were measured. The concentration of each enantiomer were then calculated using the enantiomeric ratios and the racemic propafenone concentrations previously measured. This method after validation procedures has been applied to the multisample analyses of a human pharmacokinetic study with 10 healthy volunteers after an oral dose of 300 mg propafenone hydrochloride. The method was shown to be sensitive (7.5 ng.ml-1), convenient and reproducible.

Chromatography, High Pressure Liquid↗

[Study on the polyoxygenated cyclohexenes from Uvaria boniana].

Seven new polyoxygenated cyclohexenes, named uvaribonol A-G (1-7) have been isolated from the ethanol extract of the stems of Uvaria boniana Finet. (Annonaceae), and their structures, including the absolute configuration, were determined by spectral and chemical methods. In vitro cytotoxicity test against several human tumor cell lines indicated that all of the new natural compounds are inactive, but some of the derivatives showed obvious activities. Compound 2a is the most active, exhibiting significant cytotoxicities against KB and Bel7402 cells with IC50 < 1 microgram.ml-1, and against HCT-8 cell with IC50 < 0.1 microgram.ml-1.

Annonaceae↗

[The chemical constituents of Goniothalamus howii Merr].

Two new compounds were isolated from the chloroform soluble fraction of ethanolic extract of bark of Goniothalamus howii Merr. On the basis of their chemical properties and spectral data (MS, UV, IR, 1H and 13CNMR) they were identified as 6S (1R-hydroxy-2R-cinnamyloxyphenethyl) 5, 6-dihydro-5S-hydroxy-2-pyrone named Howiinol A and 6S-(1S, 2R-epoxyphenethyl-5S-cinnamyloxy) 5, 6-dihydro-2-pyrone named Howiinin A. Howiinol A showed significant antitumor activities toward human tumor cell in vitro and in vivo and less toxic.

Animals↗

[Application of improved western blot method in diagnosis of cysticercosis].

AIM: To evaluate the diagnostic value of four specific antigens from cDNA of Cysticercus cellulosae. cC1, cC2, and cP1 and cH1 (28 kDa, 18 kDa, 14 kDa and 34 kDa), mixing in equal proportions for the diagnosis of cysticercosis. METHODS: Taking the FP (fusion proteins) as antigen to make IWB (improved Western blot) analysis basing on the detection of antibody responses against FP, and making ELISA/IHA-crude antigen(CA) analysis. They were evaluated comparatively while using 107 infected sera of cysticercosis cases, 40 infected sera of clonorchiasis cases, 24 infected sera of echinococcosis cases and 34 sera of healthy persons. The FP are encoded by cDNAs of beta-galactosidase-specific antigens of Cysticercus cellulosae isolated from the cDNA library. RESULTS: 94(87.9%) sera from 107 cysticercosis cases recognized FP in IWB and could not cross-react with the sera of echinococcosis cases, clonorchiasis cases and healthy persons, the specific rates were 100%, whereas ELISA, IHA using CA were 84.1% and 74.8%, respectively and could cross-react with the sera of echinococcosis cases, the false positive rates were 2.5% and 12.5% respectively; CA-ELISA/IHA could cross-react with the sera of clonorchiasis patients, the false positive rates were 8.3% and 16.7%, respectively; and they could also cross-react with the sera of healthy persons, the false positive rates were 8.8% and 11.8%, respectively. CONCLUSION: The recombinant FP used in the immunodiagnosis of cysticercosis is specific and sensitive.

Animals↗